(a) Field of the Invention
The present invention relates to a wireless mesh network system, a virtual node generating method of the wireless mesh network system, a unicast packet routing method, and a scheduling method. Particularly, the present invention relates to a system and method for stably generating a field, including unicast in a subset, and performing appropriate scheduling so as to improve performance of an electrostatic field model based potential routing scheme in a wireless mesh network including a plurality of nodes.
(b) Description of the Related Art
In a conventional potential routing scheme, potential values for a plurality of mesh nodes are calculated, and potential values for a plurality of gateway nodes are assigned. When transmitting a data packet at a specific node, the scheme utilizes potential values and position information on 1-hop neighboring nodes, and sets a routing path according to the information. The scheme minimizes a maintenance cost of the network path and handover delay of a moving mesh node by transmitting the data packet through a single path or multi-paths according to the routing path.
The conventional potential routing scheme is designed in consideration of communication between the wireless mesh node and the wireless mesh gateway. It further cannot solve the problem of data transmission failure at a topology including vacant areas and linear topology.
In addition, the IEEE 802.11 CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) and back-pressure scheduling has been proposed as existing scheduling schemes for the wireless environment.
The IEEE 802.11 CSMA/CA defines a method to occupy a shared wireless resource by contention. The back-pressure scheduling method is known to achieve optimization of the throughput in the infinite buffer and unicast environment, and it determines the channel occupancy order by assigning priorities to links according to queue differences among respective nodes.
However, the existing scheduling schemes are not specified to the wireless mesh environment. That is, the problem of inefficiently providing a channel access right to a specific flow exists in the IEEE 802.11 CSMA/CA based wireless mesh network.
Also, a bottleneck area near a gateway is not considered in the conventional back-pressure scheduling based wireless mesh network.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.